Triangulated Irregular Network Edge Node Face 1 3

Triangulated Irregular Network Edge Node Face 1

3 D Structure of a TIN 2

Real TIN in 3 D!

TIN with Surface Features Classroom Waller Creek UT Football Stadium

A Portion of the TIN

Input Data for this Portion Mass Points Soft Breaklines Hard Breaklines

TIN Vertices and Triangles

TIN Surface Model Waller Creek Street and Bridge

3 -D Scene

3 -D Scene with Buildings

TIN as a source of cross-sections 11

Cross. Sections 12

Channel and Cross-Section Direction of Flow Channel Cross-Section 13

HEC Geo. RAS • A set of Arc. GIS tools for processing of geospatial data for – Export of geometry HEC-RAS – Import of HEC-RAS output for display in GIS • Available from HEC at http: //www. hec. usace. army. mil/software/hec-ras/hec-georas. html • An old tutorial on using Geo. RAS for Waller Creek with Arc. View 3. x is available at: http: //www. crwr. utexas. edu/gishydro 01/Class/exercises/ georas. html 14

Hydraulic Modeling with Geo-RAS GIS data HEC-RAS Geometry HEC-RAS Flood Profiles Flood display in GIS 15

Hydraulic Modeling with HEC-RAS • Cross-section extracted from the TIN. • RAS stream geometry.

Hydraulic Modeling with HEC-RAS • Resulting water elevations.

Floodplain Mapping • Floodplain for 500 cfs.

Floodplain Mapping • 2 -D floodplain animation (500 – 5, 000 cfs).

Floodplain Mapping • 3 -D floodplain animation.